release: add docs/TESTING.md

docs/TESTING.md

@@ -1172,7 +1172,7 @@ harness outputs (`run_output.txt`, `run_final2.txt`, `run_final3.txt`), the reco
 **24 live runs, 24 correct dispatches, 0 mock nodes, no run id repeated across passes.** The trace fill
 was **94.4444 %** on every case, and every case carries a real `run_*` id, the Hugging Face link in the
 DOM, and the `capabilities → assets → infer` call sequence all addressed to
-`satquery-backend-m4yv.onrender.com` (two `assets` calls for the pair tasks).
+`<backend-host>` (two `assets` calls for the pair tasks).
 
 The eight cases are Phase A (six regression cases: `vqa`, `caption`, `grounding`, `change`,
 `change_vqa`, `optical_sar`) and Phase B (the two defect cases: `"Where are the built-up areas in this